General Principles for Counseling and Management of Triplet Pregnancies.

Compared with singleton pregnancies, triplet pregnancies are associated with a significantly increased risk of adverse pregnancy outcomes. Early ultrasound examination is the best way to diagnose triplets, establish dating, and determine the number of placentas to provide appropriate counseling and monitoring. Dichorionic placentation adds risks specifically associated with a shared placenta, and limits options for intervention. Multifetal reduction is an option that can significantly improve pregnancy outcomes compared with non-reduced triplet pregnancies. Integration of a Maternal-Fetal Medicine specialist in the prenatal care for a triplet pregnancy reduces the risk of preeclampsia, preterm birth, low birthweight infants, perinatal mortality, and major neonatal morbidity.

Clinical outcomes of vanishing twin syndrome and selective fetal reduction after double embryos transferred in IVF pregnancy: A propensity score matching study.

OBJECTIVE: The purpose of this study was to analyze the influence of early vanishing twin syndrome (VTS) and selective fetal reduction (SEFR) on surviving singleton births in in-vitro fertilization (IVF) pregnancy. METHODS: We collected patients who conceived through IVF and delivered singletons over the past six years. The VT group (n = 194) and SEFR group (n = 144) had underwent double embryos transferred (DET) and only one fetus was born, due to the subsequent one birth reduction. The SET group had one embryo transferred (SET) and gave birth to singleton. Using the propensity score matching (PSM) method to reduce confounding, the VT group and SEFR group were matched and compared with 570 and 576 singleton controls, respectively (SET-I/II group). Obstetric complications and neonatal outcomes were compared. In addition, quantity and quality of transferred embryos of VT (n = 194) and singleton groups (born with singleton after DET and matched with VT group by PSM, n = 554) were compared. RESULTS: Compared with the SET-I group, VT group had increased incidence of severe obstetric complications, including severe preeclampsia (p = 0.031), oligohydramnios (p = 0.038) and polyhydramnios (p = 0.015). VT group was more likely to show more frequent small for gestational age (SGA) (p = 0.046) and very small for gestational age (VSGA) (p = 0.031). Newborns in the SEFR group had a significantly lower birth weight (p = 0.005) and were more likely to manifest as low birthweight (LBW) (p = 0.009) and very low birthweight (VLBW, birth weight < 1500 g) (p = 0.012), and the incidence of very large for gestational age (VLGA) was lower (p = 0.030), compared with the control group. There were more developmental abnormalities in newborns of VTS, for decreased incidence of SGA (OR 0.156, 95% CI 0.036-0.669), VSGA (OR 0.057, 95% CI 0.006-0.553) and VLGA (OR 0.415, 95% CI 0.212-0.815) in SEFR group. The good quality embryo rate was higher in VT group (72.7% vs. 63.3%, p = 0.001) compared with the singleton group. CONCLUSIONS: DET with subsequent VTS/SEFR carried a higher rate of adverse clinical outcomes, and the VTS group had worse perinatal outcome compared with SEFR. Therefore, we recommend SET in ART.

Fetal Outcomes and Prognostic Factors After Radiofrequency Ablation for the Selective Reduction in Complicated Monochorionic Multiple Pregnancies.

RATIONALE AND OBJECTIVES: Monochorionic pregnancies are responsible for some severe complications, and selective reduction of a single fetus can improve pregnancy outcomes. This study evaluated the fetal outcomes and procedure-related prognostic factors after radiofrequency ablation (RFA) in complicated monochorionic multiple pregnancies. MATERIALS AND METHODS: This prospective cross-sectional study was conducted in an academic center from June 2020 to January 2022. The participants were 70 women with monochorionic multiple pregnancies who were candidates for selective fetal reduction by RFA. All participants' demographic data, RFA-related information, and pregnancy outcomes were evaluated and reported. RESULTS: The RFA procedure was successful in all participants. The most frequent RFA indications were twin-to-twin transfusion syndrome following selective intrauterine growth restriction. The mean gestational age at birth was 33.60 ± 5.62 weeks. Also, 11 (15.7%) of the cases had preterm delivery up to 30 days after RFA. The total pregnancy loss rate was 12 (17.14%), and the total fetal survival rate after RFA was 82.85%. The mean time of the RFA procedure was 130.8 ± 83.3 seconds. The procedure was conducted easily in 31 (44.2%) cases. Although the meantime of RFA procedure was longer in the not-easy group, the difference in surgery time was not significant (P = .296). There was no significant relationship (P = .623) between RFA indications and the gestational age of the remained fetus at delivery. The RFA needle was passed through the placenta in 18 (25.7%) cases. The mean gestational age at the delivery time was significantly lower in this group compared to their counterparts' gestational ages without needle placental passage (P = .030). Also, there was no significant correlation between gestational age at pregnancy termination and RFA cycles (P = .219). CONCLUSION: RFA is a relatively safe and minimally invasive procedure for the selective reduction of complicated monochorionic fetuses. Although mortality, premature membrane rupture, and preterm delivery are the potential risk factors for the remaining co-twin. According to this study, gestational age at the time of the procedure and passing the needle through the placenta can affect the outcome. Other procedure-related factors like easy- or hard-access procedures, and the number of RFA cycles are not significantly associated with gestational age at birth.

Hypertensive disorders of pregnancy after multifetal pregnancy reduction: a systematic review and meta-analysis.

OBJECTIVE: To systematically review the literature on hypertensive disorders of pregnancy (HDP) after multifetal pregnancy reduction (MFPR). METHODS: A comprehensive search in PubMed, Embase, Web of Science, and Scopus was performed. Prospective or retrospective studies reporting on MFPR from triplet or higher-order to twin compared to ongoing (i.e., non-reduced) triplets and/or twins were included. A meta-analysis of the primary outcome HDP was carried out using a random-effects model. Subgroup analyses of gestational hypertension (GH) and preeclampsia (PE) were performed. Risk of bias was assessed using the Newcastle-Ottawa Quality Assessment Scale. RESULTS: Thirty studies with a total of 9,811 women were included. MFPR from triplet to twin was associated with a lower risk for HDP compared to ongoing triplets (OR 0.55, 95% CI, 0.37-0.83; p = 0.004). In a subgroup analysis, the decreased risk of HDP was driven by GH, and PE was no longer significant (OR 0.34, 95% CI, 0.17-0.70; p = 0.004 and OR 0.64, 95% CI, 0.38-1.09; p = 0.10, respectively). HDP was also significantly lower after MFPR from all higher-order (including triplets) to twin compared to ongoing triplets (OR 0.55, 95% CI, 0.38-0.79; p = 0.001). In a subgroup analysis, the decreased risk of HDP was driven by PE, and GH was no longer significant (OR 0.55, 95% CI 0.32-0.92; p = 0.02 and OR 0.55, 95% CI 0.28-1.06; p = 0.08, respectively). No significant differences in HDP were found in MFPR from triplet or higher-order to twin versus ongoing twins. CONCLUSIONS: MFPR in women with triplet and higher-order multifetal pregnancies decreases the risk of HDP. Twelve women should undergo MFPR to prevent one event of HDP. These data can be used in the decision-making process of MFPR, in which the individual risk factors of HDP can be taken into account.

Triple trouble: uncovering the risks and benefits of early fetal reduction in trichorionic triplets in a large national Danish cohort study.

BACKGROUND: Triplet pregnancies are high risk for both the mother and the infants. The risks for infants include premature birth, low birthweight, and neonatal complications. Therefore, the management of triplet pregnancies involves close monitoring and may include interventions, such as fetal reduction, to prolong the pregnancy and improve outcomes. However, the evidence of benefits and risks associated with fetal reduction is inconsistent. OBJECTIVE: This study aimed to compare the outcomes of trichorionic triplet pregnancies with and without fetal reduction and with nonreduced dichorionic twin pregnancies and primary singleton pregnancies. STUDY DESIGN: All trichorionic triplet pregnancies in Denmark, including those with fetal reduction, were identified between 2008 and 2018. In Denmark, all couples expecting triplets are informed about and offered fetal reduction. Pregnancies with viable fetuses at the first-trimester ultrasound scan and pregnancies not terminated were included. Adverse pregnancy outcome was defined as a composite of miscarriage before 24 weeks of gestation, stillbirth at 24 weeks of gestation, or intrauterine fetal death of 1 or 2 fetuses. RESULTS: The study cohort was composed of 317 trichorionic triplet pregnancies, of which 70.0% of pregnancies underwent fetal reduction to a twin pregnancy, 2.2% of pregnancies were reduced to singleton pregnancies, and 27.8% of pregnancies were not reduced. Nonreduced triplet pregnancies had high risks of adverse pregnancy outcomes (28.4%), which was significantly lower in triplets reduced to twins (9.0%; difference, 19.4%, 95% confidence interval, 8.5%-30.3%). Severe preterm deliveries were significantly higher in nonreduced triplet pregnancies (27.9%) than triplet pregnancies reduced to twin pregnancies (13.1%; difference, 14.9%, 95% confidence interval, 7.9%-21.9%). However, triplet pregnancies reduced to twin pregnancies had an insignificantly higher risk of miscarriage (6.8%) than nonreduced twin pregnancies (1.1%; difference, 5.6%; 95% confidence interval, 0.9%-10.4%). CONCLUSION: Triplet pregnancies reduced to twin pregnancies had significantly lower risks of adverse pregnancy outcomes, severe preterm deliveries, and low birthweight than nonreduced triplet pregnancies. However, triplet pregnancies reduced to twin pregnancies were potentially associated with a 5.6% increased risk of miscarriage.

Perinatal outcome after selective fetal reduction in monochorionic twin pregnancies: A comparison of techniques over a 20-year period.

OBJECTIVE: To assess the perinatal outcome after fetal reduction in complicated monochorionic (MC) twin pregnancies by comparing different techniques. METHODS: A retrospective cohort study at a national referral center comparing data between four techniques: interstitial laser coagulation, radiofrequency ablation (RFA), fetoscopic laser coagulation (FLC) and bipolar cord coagulation (BCC). The primary outcome was the mortality of the co-twins. Secondary outcomes were preterm pre-labor rupture of membranes (PPROM), gestational age at delivery and neonatal morbidity. RESULTS: 259 MC twin pregnancies underwent selective fetal reduction: 29 IL, 64 RFA, 85 FLC and 81 BCC. The perinatal mortality rate was 29% and fetal demise of the co-twins occurred in 19%. The lowest mortality rate was seen after BCC (17%, p = 0.012). PPROM occurred in 18% patients without significant differences between techniques. The mean gestational age at delivery in liveborn children was 35 weeks and did not differ between techniques. Severe cerebral injury and neonatal morbidity were reported in 4% and 14%, respectively, without significant differences between techniques. CONCLUSIONS: Selective fetal reductions in MC twins are precarious procedures with an increased risk of perinatal mortality of the co-twins. Our results show the lowest mortality rates after BCC. However, high PPROM rates were seen irrespective of the technique.

Risks and pregnancy outcome after fetal reduction in dichorionic twin pregnancies: a Danish national retrospective cohort study.

BACKGROUND: Twin pregnancies carry a higher risk of congenital and structural malformations, and pregnancy complications including miscarriage, stillbirth, and intrauterine fetal death, compared with singleton pregnancies. Carrying a fetus with severe malformations or abnormal karyotype places the remaining healthy fetus at an even higher risk of adverse outcome and pregnancy complications. Maternal medical conditions or complicated obstetrical history could, in combination with twin pregnancy, cause increased risks for both the woman and the fetuses. To our knowledge, no previous studies have evaluated and compared the outcomes of all dichorionic twin pregnancies and compared the results of reduced twins with those of nonreduced and primary singletons in a national cohort. These data are important for clinicians when counseling couples about fetal reduction and its implications. OBJECTIVE: This study aimed to describe and compare the risks of adverse pregnancy outcomes, including the risk of pregnancy loss, in a national cohort of all dichorionic twins-reduced, nonreduced, and primary singletons. In addition, we examined the implications of gestational age at fetal reduction on gestational age at delivery. STUDY DESIGN: This was a retrospective cohort study of all Danish dichorionic twin pregnancies, including pregnancies undergoing fetal reduction and a large proportion of randomly selected primary singleton pregnancies with due dates between January 2008 and December 2018. The primary outcome measures were adverse pregnancy outcomes (defined as miscarriage before 24 weeks, stillbirth from 24 weeks, or single intrauterine fetal death in nonreduced twin pregnancies), preterm delivery, and obstetrical pregnancy complications. Outcomes after fetal reduction were compared with those of nonreduced dichorionic twins and primary singletons. RESULTS: In total, 9735 dichorionic twin pregnancies were included, of which 172 (1.8%) were reduced. In addition, 16,465 primary singletons were included. Fetal reductions were performed between 11 and 23 weeks by transabdominal needle-guided injection of potassium chloride, and outcome data were complete for all cases. Adverse pregnancy outcome was observed in 4.1% (95% confidence interval, 1.7%-8.2%) of reduced twin pregnancies, and 2.4% (95% confidence interval, 0.7%-6.1%) were delivered before 28 weeks, and 4.2% (95% confidence interval, 1.7%-8.5%) before 32 weeks. However, when fetal reduction was performed before 14 weeks, adverse pregnancy outcomes occurred in only 1.4% (95% confidence interval, 0.0%-7.4%), and delivery before 28 and 32 weeks diminished to 0% (95% confidence interval, 0.0%-5.0%) and 2.8% (95% confidence interval, 0.3%-9.7%), respectively. In contrast, 3.0% (95% confidence interval, 2.7%-3.4%) of nonreduced dichorionic twins had an adverse pregnancy outcome, and 1.9% (95% confidence interval, 1.7%-2.1%) were delivered before 28 weeks, and 7.3% (95% confidence interval, 6.9%-7.7%) before 32 weeks. Adverse pregnancy outcomes occurred in 0.9% (95% confidence interval, 0.7%-1.0%) of primary singletons, and 0.2% (95% confidence interval, 0.1%-0.3%) were delivered before 28 weeks, and 0.7% (95% confidence interval, 0.6%-0.9%) before 32 weeks. For reduced twins, after taking account of maternal factors and medical history, it was demonstrated that the later the fetal reduction was performed, the earlier the delivery occurred (P<.01). The overall risk of pregnancy complications was significantly lower among reduced twin pregnancies than among nonreduced dichorionic twin pregnancies (P=.02). CONCLUSION: In a national 11-year cohort including all dichorionic twin pregnancies, transabdominal fetal reduction by needle guide for fetal or maternal indication was shown to be safe, with good outcomes for the remaining co-twin. Results were best when the procedure was performed before 14 weeks.

Fetal Reduction Could Improve but Not Completely Reverse the Pregnancy Outcomes of Multiple Pregnancies: Experience From a Single Center.

Objective: To investigate the effectiveness and limitations of multifetal pregnancy reduction (MFPR) on the improvement of pregnancy outcomes of triplet or twin pregnancies conceived by in vitro fertilization (IVF) or intracytoplasmic sperm injection (ICSI). Methods: We performed a cohort study of women undergoing IVF or ICSI from 2002-2016 in reproductive center, women's hospital, Zhejiang University School of Medicine. The cohort included 502 women who underwent MFPR and 9641 non-reduced women. Pregnancy outcomes were gestational age (GA) at delivery, pregnancy loss, preterm delivery, low birth weight (LBW), very low birth weight (VLBW), and small for gestational age (SGA). Multiple linear regression and logistic regression models were used to compare pregnancy outcomes between groups. Results: Triplets reduced to singletons had a longer median GA (39.07 vs 37.00, P<0.001), and lower rates of LBW (8.9% vs 53.2%, P<0.001) and SGA (17.8% vs 44.7%, P=0.001) than triplets reduced to twins, with a similar pregnancy loss rate (6.7% vs 6.6%, P=0.701). Twins reduced to singletons had a comparable pregnancy loss rate (4.8% vs. 6.5%, P=0.40), a longer median GA (38.79 vs. 37.00, P<0.001), and lower rates of LBW (13.5% vs. 47.0%, P<0.001) and SGA (13.5% vs. 39.6%, P<0.001) than primary twins. Triplets reduced to twins had higher rates of LBW (53.2% vs. 47.0%, P=0.028) and SGA (44.7% vs. 39.6%, P=0.040) than primary twins, with a similar pregnancy loss rate (6.6% vs. 6.5%, P=0.877). Singletons reduced from triplets/twins had higher rates of preterm delivery (15.8% vs. 7.3%, P<0.001), LBW (12.3% vs. 4.32%, P<0.001), VLBW (2.3% vs. 0.4%, P=0.002), and SGA (14.6% vs.6.6%, P<0.001) than primary singletons, with a comparable pregnancy loss rate (5.3% vs. 5.4%, P=0.671). Conclusions: This study suggests that the pregnancy loss rate is similar between reduction and non-reduction groups. MFPR improves pregnancy outcomes, including the risk of preterm delivery, LBW, and SGA, but still could not completely reverse the adverse pregnancy outcomes of multiple pregnancies.

The clinical outcomes of selective and spontaneous fetal reduction of twins to a singleton pregnancy in the first trimester: a retrospective study of 10 years.

BACKGROUND: Singleton pregnancy is encouraged to reduce pregnancy complications. In addition to single embryo transfer (SET), selective and spontaneous fetal reduction (SEFR and SPFR) can also achieve singleton pregnancies. After SEFR or SPFR, an inanimate fetus remains in the uterus. It is unclear whether the inanimate fetus would adversely affect another fetus or the mother. Previous studies have focused on the differences between pre- and post-reduction. However, studies focusing on the influence of SEFR and SPFR on the remaining fetal development and maintenance of pregnancy are rare. METHODS: Materials from 5922 patients whose embryo transfer dates ranged from March 2011 to January 2021 were collected. Both the SEFR group (n = 390) and SPFR group (n = 865) had double embryos transferred (DET) and got twin pregnancies, but subsequent selective or spontaneous fetal reduction occurred. The SET group (n = 4667) had only one embryo transferred. All were singleton pregnancies on the 65th day after embryo transfer. Clinical outcomes, including pregnancy outcomes, pregnancy complications, and newborn outcomes, were compared among the three groups. RESULTS: After adjusting for age, infertility duration, types of infertility, states of embryos, body mass index, and factors affecting SET or DET decisions, multivariate regression analysis revealed that SEFR increased the risk of miscarriage (OR 2.368, 95% CI 1.423-3.939) and preterm birth (OR 1.515, 95% CI 1.114-2.060), and reduced the gestational age (ßeta -0.342, 95% CI -0.544- -0.140). SPFR increased the risk of gestational diabetes mellitus (GDM) (OR 1.657, 95% CI 1.215-2.261), preterm premature rupture of membranes (PPROM) (OR 1.649, 95% CI 1.057-2.574), and abnormal amniotic fluid volume (OR 1.687, 95% CI 1.075-2.648). Both SEFR and SPFR were associated with reduced live birth rate (OR 0.522, 95% CI 0.330-0.825; OR 0.671, 95% CI 0.459-0.981), newborn birth weight (ßeta -177.412, 95% CI -235.115--119.709; ßeta -42.165, 95% CI -83.104--1.226) as well as an increased risk of low-birth-weight newborns (OR 2.222, 95% CI 1.490-3.313; OR 1.510, 95% CI 1.092-2.087). CONCLUSIONS: DET with subsequent fetal reduction was related to poor clinical outcomes. We recommend that DET with subsequent fetal reduction should only be considered as a rescue method for multiple pregnancy patients with potential complications, and SET is more advisable.

Outcome of monochorionic triamniotic triplet pregnancies: Expectant management versus fetal reduction.

OBJECTIVE: To compare the outcomes of monochorionic triamniotic (MCTA) triplets managed expectantly with those reduced to twins. METHOD: This was a retrospective cohort study comparing expectant management (EM) with fetal reduction (FR) to twins in 43 consecutive MCTA triplets with 3 live fetuses at 11-14 weeks between 2012 and 2021. RESULTS: Nineteen patients managed expectantly and 24 triplets reduced to twins were included. The rate of pregnancy with at least one survivor was 84.2% in the EM group and 66.7% in the FR group (P = 0.190). Compared to the EM cases, triplets reduced to twins had a higher median gestational age at delivery (36.0 vs. 33.3 weeks; P < 0.001), a higher mean birth weight (2244.3 ± 488.6 g vs. 1751.1 ± 383.2 g; P < 0.001) and a lower risk of preterm birth before 34 weeks (11.8% vs. 64.7%; P = 0.001). There were no significant differences in the risk of miscarriage, pregnancy complications and composite adverse neonatal outcomes. CONCLUSION: In MCTA triplets, FR to twins could reduce the risk of preterm birth, whereas EM seems to be a reasonable choice when the priority is at least one survivor. However, due to the small sample size of this study, these findings must be interpreted with great caution.

A case of aplasia cutis congenita following fetal reduction of triplet pregnancy conceived through in vitro fertilization.

BACKGROUND: Aplasia cutis congenita (ACC) is a rare congenital localized skin defect that is mostly diagnosed in the newborn or infant period. ACC type 5 often involves the trunk or extremities accompanied by fetus papyraceous (FP) or placental infarcts. The etiology and pathogenesis of this rare type of ACC are not well known. In this case, we report an ACC type 5 with a definite etiology. CASE: We report a preterm infant with ACC type 5, with diffuse bilateral leg lesions found at birth. He was the first baby of dichorionic twin after reduction from a dichorionic triplet pregnancy conceived through in vitro fertilization. A fetus papyraceous was found in juxtaposition with the affected baby`s placenta. After 37 days of hospitalization, his leg lesions were successfully epithelized with supportive care. He is regularly visiting the Dermatology clinic for scar care and shows normal development without motor limitation. CONCLUSIONS: Herein, we present a preterm infant with ACC type 5 and the placental pathology with fetus papyraceous of the artificially reduced monochorionic co-twin of the affected infant. We suggest a precautious decision in multifetal pregnancy reduction (MFPR) in dichorionic triplets, presenting ACC type 5 as an adverse outcome of MFPR.

The effects of early or late multifetal reduction procedure on perinatal outcomes in multiple pregnancies reduced to twins or singletons: A single tertiary center experience.

OBJECTIVE: The aim of the study was to compare the effect of early or late fetal reduction (FR) procedures on perinatal outcomes in multiple pregnancies reduced to twins or singletons. STUDY DESIGN: This retrospective cohort study consisted of data from a single tertiary center between January 2013 and December 2020 and included 103 women with multiple pregnancies between 8 and 14 gestational weeks and who underwent FR by transabdominal approach. Late FR was defined as 11-13 6/7 gestational weeks (Group L) and early FR was defined as 8-10 6/7 gestational weeks (Group E) in the study. All pregnancies with FR were named Group S (Single) if reduced to singletons and Group T (Twin) if reduced to twin pregnancies. RESULTS: Thirty four percent (n = 35) were reduced to single pregnancy, the remaining 66% of these cases (n = 68) were reduced to twin pregnancy. The overall survival rate was 90%.When the cases were examined in terms of pregnancy complications, it was observed that the PPROM rate and preterm labor rate in the Group T were statistically significantly higher than the Group S (p = 0.015 and p < 0.001, respectively). When comparing the overall survival results between Group S and Group T, it was found that the overall survival of Group S was statistically significantly better (p < 0.001). When Group E and Group L were compared in terms of their pregnancy course and neonatal outcomes, no statistically significant difference was found between them. No statistically significant difference was found between the complication rates in the first week after the procedure (p < 0.05). Neonatal intensive care need was found at a rate of 31% in those with Group E, while this rate was found as 39% in Group L, and this difference was also not statistically significant (p = 0.480). When the preterm labor rate was compared between these two groups, there was no statistically significant difference in all three subgroups (<32nd, <34th, and <37th gestational weeks). CONCLUSION: When FR to singleton is required for fetal or maternal reasons, it should be discussed with the parents that the risk of fetal loss is similar to FR to twins, but the effect on perinatal survival is more favorable than expected.

Clinical outcomes in higher-order multiples reduced to dichorionic diamniotic (DCDA) twins compared with primary twins and singletons: A prospective observational study.

OBJECTIVE: To compare outcomes in higher-order multiple pregnancies reduced to dichorionic diamniotic (DCDA) twins with primary DCDA twins and singleton pregnancies. METHODS: This prospective observational study included all higher-order multiple pregnancies that underwent ultrasound-guided transabdominal fetal reduction at 11-13 weeks of gestation from January 2018 to June 2020. Outcomes were compared with 100 primary DCDA twins and 1078 singletons. RESULTS: Sixty-four higher-order multiples underwent reduction at mean gestational age of 11.46 weeks. Of the reduced pregnancies, 3.12% resulted in miscarriage before 24 weeks compared with 2% (2/100) of primary twins and 0.74% of singletons (P = 0.09). The mean gestational age at delivery was 33.48 weeks for reduced twins, 34.52 weeks for primary twins (P = 0.10) and 38.14 weeks for singletons (P < 0.001). Compared with primary twins, the adjusted odds of preterm delivery before 34 weeks and before 36 weeks for reduced twins were 0.56 (95% confidence interval [CI] 0.48-3.54, P = 0.62) and 0.84 (95% CI 0.78-8.85, P = 0.08), respectively. There was no significant difference in rates of pre-eclampsia, Cesarean delivery, birth weight below the 10th and 3rd centiles, and perinatal mortality among primary and reduced twins. All risks were significantly lower in singleton pregnancies. CONCLUSION: Reduced twins have similar obstetric and perinatal outcomes as primary twins, but adverse outcomes are significantly higher in both groups when compared with singleton pregnancies.

Fetal reduction and twins.

Infertility treatments have allowed millions of couples to have their own children, but resultant multiple pregnancies with their increased morbidity and mortality have been a significant complication. Fetal reduction was developed to ameliorate this issue. Over 30 years of publications show that fetal reduction has been highly successful in substantially reducing both mortality and morbidity related to multiple pregnancies. As with most radically new techniques, initial cases were in the "nothing to lose" category. With experience, indications liberalize, and quality of life issues gain relevance. The overall risks of twin pregnancy are not twice that of singleton pregnancy; they are about 4 to 5 times higher. In experienced hands, the combination of genetic testing by chorionic villus sampling followed by fetal reduction has made the outcomes of most multiple pregnancies statistically equivalent to those of pregnancies with lower fetal numbers. Use of microarray analysis to better determine fetal genetic health before deciding on which fetus(es) to keep or reduce further improves pediatric outcomes. With increasing experience and lower average starting numbers, the proportion of fetal reductions to a singleton has increased considerably. Twins to a singleton fetal reductions now constitute an increasing proportion of cases performed. Data on such cases show improved outcomes, and we believe fetal reduction should be at least discussed and offered to all patients with a dichorionic twin pregnancy or higher. With the increasing reliance on elective single-embryo transfers, monochorionic twins, which have much higher complication rates than dichorionic twins, have increased substantially. Furthermore, monochorionic twins cannot be readily and safely reduced, so the adverse perinatal statistics of elective single-embryo transfer are a major setback for good outcomes. Although elective single-embryo transfer is appropriate for some, we believe that for many couples, the transfer of 2 embryos is generally a more rational approach.

Optimal timing of fetal reduction from twins to singleton: earlier the better or later the better?

OBJECTIVES: To determine the rate of pregnancy complications and adverse obstetric and neonatal outcomes of twin pregnancies that were reduced to singleton at an early compared with a later gestational age. METHODS: This was a historical cohort study of dichorionic diamniotic twin pregnancies that underwent fetal reduction to singletons in a single tertiary referral center between January 2005 and February 2017. The study population was divided into two groups according to gestational age at fetal reduction: those performed at 11-14 weeks' gestation, mainly at the patient's request or as a result of a complicated medical or obstetric history; and selective reductions performed at 15-23 weeks for structural or genetic anomalies. The main outcome measures compared between pregnancies that underwent early reduction and those that underwent late reduction included rates of pregnancy complications, pregnancy loss, preterm delivery and adverse neonatal outcome. RESULTS: In total, 248 dichorionic diamniotic twin pregnancies were included, of which 172 underwent early reduction and 76 underwent late reduction. Although gestational age at delivery was not significantly different between the late- and early-reduction groups (38 weeks, (interquartile range (IQR), 36-40 weeks) vs 39 weeks (IQR, 38-40 weeks); P = 0.2), the rates of preterm delivery < 37 weeks (28.0% vs 14.0%; P = 0.01), < 34 weeks (12.0% vs 1.8%; P = 0.002) and < 32 weeks (8.0% vs 1.8%; P = 0.026) were significantly higher in pregnancies that underwent late reduction. Regression analysis revealed that late reduction of twins was an independent risk factor for preterm delivery, after adjustment for maternal age, parity, body mass index and the location of the reduced sac. Rates of early complications linked to the reduction procedure itself, such as infection, vaginal bleeding and leakage of fluids, were comparable between the groups (7.0% for early reduction vs 9.2% for late reduction; P = 0.53). There was no significant difference in the rate of pregnancy loss before 24 weeks (0.6% for early reduction vs 1.3% for late reduction; P = 0.52), and no cases of intrauterine fetal death at or after 24 weeks were documented. There was no significant difference in the prevalence of gestational diabetes mellitus, hypertensive disorders of pregnancy, preterm prelabor rupture of membranes or small-for-gestational age. The rates of respiratory distress syndrome (6.7% vs 0%; P = 0.002), need for mechanical ventilation (6.7% vs 0.6%; P = 0.01) and composite neonatal morbidity (defined as one or more of respiratory distress syndrome, sepsis, necrotizing enterocolitis, intraventricular hemorrhage, need for respiratory support or neonatal death) (10.7% vs 2.9%; P = 0.025) were higher in the late- than in the early-reduction group. Other neonatal outcomes were comparable between the groups. CONCLUSIONS: Compared with late first-trimester reduction of twins, second-trimester reduction is associated with an increased rate of prematurity and adverse neonatal outcome, without increasing the rate of procedure-related complications. Technological advances in sonographic diagnosis and more frequent use of chorionic villus sampling have enabled earlier detection of fetal anatomic and chromosomal abnormalities. Therefore, efforts should be made to complete early fetal assessment to allow reduction during the first trimester. Copyright © 2020 ISUOG. Published by John Wiley & Sons Ltd.

Transabdominal fetal reduction: a report of 124 cases.

To prevent fetal loss, preterm delivery, and perinatal morbidity of multifetal pregnancies (MPs), fetal reduction (FR) is offered to some patients. We retrospectively analysed the data of 124 MPs that underwent transabdominal FR to twin (n = 63) and singleton (n = 61) pregnancies at a mean gestational age of 12 + 6 weeks between December 2006 and January 2018. FR was performed transabdominally with the injection of potassium chloride into the intracardiac or intrathoracic space of the fetus or fetuses after ultrasound screening for nuchal translucency and anatomical defects. The initial number of embryos were 48 twins, 63 triplets, 11 quadruplets, and 2 quintuplets. The procedure-related pregnancy loss rate was 0.8% (1/124), the overall pregnancy loss rate was 2.4% (3/124), the fetal loss rate was 1.6% (2/124), and the neonatal death rate was 0.8% (1/124). The baby take-home rates were 96% for twin pregnancies and 96.7% for singletons. This study shows that transabdominal FR is an effective and safe procedure with a pregnancy loss rate of 2.4%.Impact statementWhat is already known on this subject? The incidence of multifetal pregnancies has increased over the years. Because multifetal pregnancies increase perinatal morbidity and mortality due to prematurity, fetal reduction is offed to some patients.What the results of this study add? The results of this study add to the growing body of research on fetal reduction. The study showed that transabdominal fetal reduction is a safe procedure with a pregnancy loss rate of 2.4%.What the implications are of these findings for clinical practice and/or further research? The results of this study can be used in counselling couples with multifetal pregnancies who are considering fetal reduction. Further research is needed to confirm the current findings.

Pregnancy and birth outcomes of multiple gestations with PPROM occurred within 24 h after fetal reduction: A case series.

OBJECTIVE: The study aims to analyze the pregnancy outcomes of multiple gestations with preterm premature rupture of membranes (PPROM) that occurred within 24 h after fetal reduction with potassium chloride (KCL). MATERIALS AND METHODS: We identified and evaluated the outcomes of 16 retrospectively recorded multigestational pregnancies that met the inclusion criteria between 2006 and 2016, from the Obstetrics Department of Shandong Provincial Hospital. A total of 16 patients carrying twins or higher order multiple gestations experienced PPROM within 24 h after fetal reduction, and all of them received expectant management after understanding the relevant risks. The maternal and neonatal records were retrospectively collected and reviewed. Every surviving child was followed up to at least 2 years old. RESULT: Of the 16 cases, 12 cases (75%) ended in successful pregnancy, resulting in the delivery of at least 1 child surviving from a multiple gestational pregnancy. All cases of successful pregnancies were either term (≥37 weeks) or near-term (36+5 weeks) at delivery. And of those 20 infants delivered, only 3 were low birth weight infants (<2500g) (15%), None of the 16 women had fever, or other clinical symptoms and signs of chorioamnionitis during hospital stay. Postnatal follow-up of the surviving babies showed no obvious sequelae thus far. No newborn baby had neonatal complications, or needed to be transferred to neonatal intensive care unit. CONCLUSION: Overall, our data demonstrate that dichorionic diamniotic (DCDA) twins or higher-order gestations who experienced PPROM of the reduced fetus within 24 h after selective reduction with KCL had relatively good outcomes with expectant management alone.

Management of monochorionic twins discordant for structural fetal anomalies.

OBJECTIVE: To review the perinatal management and outcomes of monochorionic twin pregnancies (MC) discordant for congenital anomalies (DCA). METHODS: Retrospective, study of all MC DCA cases referred to our tertiary referral center from 1997 to 2018. We excluded cases complicated with twin-to-twin transfusion syndrome, twin anemia-polycythemia sequence, twin reversed arterial perfusion sequence or selective intra-uterine growth restriction. Patients were counseled about the possibility of expectant (EM) or interventional management (selective feticide [SF] or termination of the entire pregnancy [TOP]). RESULTS: One hundred eight of 4157 (2.6%) MC pregnancies were discordant for anomaly. Fifty two of 108 n(48.1%) underwent SF at a mean gestational age of 31.4 ± 5.9 weeks while 52/108(48.1%) opted for EM. Livebirth rate of the healthy co-twin was similar between the two groups (SF: 88.5% vs EM: 82.7%, P = .87). In the SF group, six healthy co-twins (6/52, 11.5%) died 5.3 ± 3.1 days after SF of the abnormal co-twin. In the EM group, in-utero demise of the abnormal twin occurred in 9 of 52 (17.3%) of the cases and was followed by the spontaneous demise of the healthy co-twin in 4 of 9 (44.4%) of these cases. CONCLUSION: Selective feticide does not seem to significantly alter survival of the healthy co-twin compared to EM.

Intrafetal laser for midtrimester TRAP sequence-experience from a single center.

OBJECTIVE: To report our experience and evaluate outcomes in monochorionic pregnancies with Twin Reversed Arterial Perfusion sequence with intrafetal laser therapy. METHODS: Retrospective review of records of all pregnancies with TRAP sequence treated by intrafetal laser therapy between 2011 January and 2015 December that were retrieved and analysed. RESULTS: Electronic search of the scan database retrieved 57 cases of TRAP sequence during the study period, 7 triplets and 50 monochorionic twins. Intrafetal laser was done in 27 cases, 22 cases of twins and 5 cases of triplets. In the twins group, median gestational age at intervention was 22.5 weeks, the earliest done at 16.3 weeks. The median gestational age at delivery and birth weight was 37 weeks and 2.5 Kgs. The median procedure and delivery interval was 14 weeks. Live birth rate was 17/22 (77%) the pump survival rate was 16/22 (73%). Pregnancies with non-surviving pump were 5 in numbers (5/22). A repeat procedure was warranted in one case. In the triplet group, median gestational age at intervention, delivery and procedure delivery interval was 18, 35 and 17 weeks. CONCLUSION: Intrafetal laser is simple, effective and the treatment of choice to interrupt the vascular supply to acardiac twin.

Is it worth reducing twins to singletons after IVF-ET? A retrospective cohort study using propensity score matching.

INTRODUCTION: Many studies have shown that multifetal reduction of high-order multiple pregnancies results in improved pregnancy outcomes. However, whether conducting elective fetal reduction from dichorionic twins after in vitro fertilization (IVF) is worthwhile remains controversial. This study aimed to determine whether elective fetal reduction of dichorionic twins after IVF and embryo transfer (IVF-ET) is associated with increased take-home baby rate. MATERIAL AND METHODS: This was a retrospective cohort study of 3600 dichorionic twin pregnancies after IVF-ET. The reduced group included 71 women with transvaginal elective fetal reduction between 7 and 8 weeks of gestation. The control group (n = 3529) comprised women who were managed expectantly. Propensity score matching was conducted before pregnancy outcomes were compared. RESULTS: The take-home baby rate was significantly lower in the reduced group (83.1% vs 92.8%, P = 0.004). The total miscarriage rate was significantly higher in the reduced group (12.7% vs 6.2%, P = 0.04). Although preterm delivery rate was lower in the reduced group (P < 0.001), over 90% were over 32 weeks, whereas the proportions were equal in the reduced group. CONCLUSIONS: In dichorionic twin pregnancies after IVF-ET, elective fetal reduction to singleton significantly decreased the chance of taking home live babies.